A rare side effect from the Moderna coronavirus vaccine may actually a good sign, according to health experts.
Some recipients have reported experiencing ‘Covid arm,’ in which people experience itchy and swollen skin, sometimes accompanied by red lumps or hives.
But the splotch is a harmless response from the immune system to the shot that fades within a week.
In fact, Dr Peter Chin-Hong, a professor of medicine and infectious disease specialist at the University of California, San Francisco, says such a reaction is an indication that your body is ramping up to prevent a potential infection in the future.
Some patients have reported a rare side effect, dubbed ‘COVID arm,’ which appears as a red and swollen splotch, that is often painful to the touch after receiving the Moderna vaccine
Health officials say the rash appears to be harmless and will often fade on its own within a few days time with treatments such as ice and Tylenol
Chin-Hong said the reactions shouldn’t be a cause of concern but rather a ‘celebration.’
‘First cause for celebration is the reaction that you’re feeling is your immune system working and getting ready to protect you,’ he said.
‘The second cause for celebration is it goes away and doesn’t really linger.’
The official term used by dermatologists and allergists to describe the side effect is ‘delayed cutaneous hypersensitivity.’
Cutaneous means affecting the skin, hypersensitivity mean an unwanted reaction produced by the immune system and delayed because it typically occurs days after the shot is given.
One infectious disease specialist said the side effect (pictured) is a good sign because it the immune system is ramping up and being trained to fight the infection
The rash is typically red and swollen, and sometime painful to the touch, and always appears on the arm in which the vaccine was administered.
Such reactions have also been found in people who’ve received tetanus vaccines, the chickenpox vaccine and the MMR (measles, mumps, rubella) vaccine.
But COVID arm has only occurred in people who received Moderna’s COIVD-19 vaccine, not Pfizer’s, and has been reported in their clinical trials.
Chin-Hong told DailyMail.com that he likens the side effect to the immune system being in a military-style boot camp.
‘The boot camp is a gradual process. In the beginning, the antibodies or the fighting soldier cells that you develop aren’t fully trained,’ he said
‘Then they’re being trained and in that process of training, they get very excited or anxious or angry, because they’re working hard and they become very good over time.’
That ‘angry’ feeling from the solider can manifest as COVID arm, but eventually goes away on its own.
Chin-Hong says this is the immune system being primed for if you actually get infected with coronavirus.
‘So when you get the second shot, they’re all ready to pounce on this thing that looks like what they’ve been training all their lives for,’ he said.
‘But then it’s not the real deal COVID so they just go back into the base.’
However, he did say that if people don’t experience the reaction, there’s no cause for panic because in clinical trials, half the participants didn’t experience any side effects.
‘If you don’t get it, doesn’t meant your immune system isn’t working,’ he explained.
If you do experience a reaction, trying moving your home or using a hot compress and, if those don’t work, take Tylenol or ibuprofen.
But most of all, Chin-Hong says that whether your reaction is a headache or COVID arm, it’s better than the long-term consequences of COVID-19.
‘From the most common to things not related to the vaccine, it’s a hell of a lot easier to get something and deal with it in a temporary basis rather than the longer acting effects of COVID and the uncertainty of how sick you’ll get and the potentially long hauler syndrome, where you’ll have symptoms linger for months and months and months,’ he said.